Causes onion yellow dwarf: stunting of first-year onion (Allium cepa) plants, with the leaves showing irregular yellow striping to almost complete yellowing, downward curling, flattening, crinkling and flaccidity. Also causes deterioration during storage and premature sprouting of onion bulbs. In onion seed plants, the virus causes striping, curling and distortion of flower stems, reduction in the number of flowers and seeds, and impairment of seed quality. In shallot (A. ascalonicum) leaf symptoms are similar, but leaf curling and plant stunting is often more severe.